Impact of the Cardiopulmonary Bypass and Cross-Clamp Time Ratio on Postoperative Outcomes in Open Heart Surgery: A Prospective Observational Analysis

Open heart surgery involves several distinct stages: 1) preparation for cardiopulmonary bypass (CPB), 2) the CPB phase, which includes the cross-clamp (CC) process, and 3) hemostasis and closure. During the CPB phase, the left internal mammary artery (LIMA) and saphenous vein are freed for coronary anastomosis, followed by arterial and venous cannulation. Once cannulation is completed, CPB is initiated. A cross-clamp is placed on the aorta to stop the heart, and cardioplegia solution is administered. Afterward, distal anastomoses are performed, and once completed, the cross-clamp is removed and the heart begins to beat again. The duration the cross-clamp remains in place is referred to as the CC time. In the CPB phase, proximal anastomoses are made on the aorta. After checking for any bleeding, thoracic drains are placed, and the CPB is terminated. Once all controls are in place, the chest is closed, and the patient is transferred to the intensive care unit.

The mortality rate for open heart surgery varies between 1% and 5%, depending on the patient's specific characteristics. Postoperative complications such as bleeding revision, acute kidney injury, liver failure, respiratory failure, and heart failure are common. Literature has linked these complications to vascular conditions, CPB time, and the duration of cross-clamp time. However, no studies were found that specifically compare the ratio of CPB time to CC time with postoperative complications.

In this study, we aim to prospectively investigate the relationship between the ratio of CPB time to cross-clamp time and postoperative complications in patients undergoing open heart surgery.